file copy from nt4>w2pro takes longer

I have two boxes side by side, one a win2k pro sp2, the other a NT4 ws sp4. Both have 100mb connections. I had a large file I wanted to copy off an NT4.0 sp6 server. the win2k box wanted to take 150 minutes, the nt box wanted 18, the 98 box took 12 minutes for the same file……anyone have any idea whats wrong?